Issue in the SAML SSO Integration

I was evaluating Adobe Sign with our IDP but I am facing an issue.
Initially, Adobe sign sends the authentication request to our IDP for credentials. I entered our credentials and then our IDP sends the authentication response back to Adobe Sign. Till here everything seems fine but after that when it redirects to Adobe Sign then instead of logged in I am facing an issue – “Corporate Sign on failed. Please contact your account administrator”.